Tuning the critical magnetic field of the triplon Bose–Einstein condensation in Ba3-xSrxCr2O8

Abstract

The structure and magnetic interactions of the triplon Bose–Einstein condensation candidates Ba _3 Cr _2 O _8 and Sr _3 Cr _2 O _8 have been studied thoroughly in the literature, but little is known about a possible triplon condensation in the corresponding solid solution ${\mathrm{Ba}}_{3-x}$ Sr _x Cr _2 O _8 . We have prepared various members of this solid solution and systematically examined their magnetic properties in high magnetic fields up to $60\;{\rm{T}}$ and at low temperatures down to $340\;\mathrm{mK}$ , by means of pulsed field and cantilever magnetometry. From these experiments for $x\in \{3,2.9,2.8,2.7,2.6,2.5\}$ , we find that the critical fields of ${\mathrm{Ba}}_{3-x}$ Sr _x Cr _2 O _8 decrease monotonically with decreasing Sr content x . This change is in good agreement with the earlier reported variation of the magnetic interactions in these compounds.

Keywords

• triplon BEC
• high field magnetometry
• magnetic phase transition